In this tutorial, I'll show you how to test the manifold absolute pressure (MAP) sensor on your 2.5L V6 equipped Stratus (Cirrus, Avenger, or Sebring) using a simple multimeter.
Contents of this tutorial:
Symptoms Of A BAD MAP Sensor
At its core, the fuel system on your 2.5L V6 equipped Stratus (Cirrus, Avenger, or Sebring) is a speed density type system. What does this mean? That the PCM relies heavily on a manifold absolute pressure (MAP) sensor to help calculate the amount of air entering the engine.
So when the manifold absolute pressure (MAP) sensor fails the engine management system is gonna' resent it and cause terrible engine performance.
The most obvious symptom of a failed MAP sensor is the check engine light (CEL) will be shining nice and bright. If your PCM is doing its job, you'll have a specific MAP sensor trouble code stored in its memory (which you can retrieve with a scan tool or code reader).
Here's a list of the symptoms you'll see with a failed MAP sensor:
- Diagnostic trouble codes (DTCs):
- P0107: MAP Sensor Voltage Too Low.
- P0108: MAP Sensor Voltage Too High.
- Hard start (in other words: the engine cranks for a long while before it finally starts).
- Black smoke coming out of the tail-pipe when the engine is running.
- Doesn't pass the smog check.
- Engine cranks but does not start.
Let's jump into the first test in the next subheading...
TEST 1: Checking The MAP Sensor Signal
Since the MAP sensor's job is to measure the intake manifold's vacuum (as the engine runs)... in this first test, we're gonna' check that the MAP sensor is creating a proper voltage signal when we manually apply vacuum to it.
This is pretty easy test, but it does require that you apply vacuum to the MAP sensor either with a vacuum pump or, if you don't have a vacuum pump, your mouth.
NOTE: The ignition key must be in the On position and MAP sensor must remain connected to its connector during this test.
Alright, this is what you need to do:
Remove the MAP sensor from its place on the intake manifold.
IMPORTANT: The MAP sensor must remain connected to its electrical connector to test for the MAP signal.
Connect your vacuum pump to the MAP sensor's vacuum port using a vacuum hose. Before you proceed to the next step, make sure the MAP sensor is connected to its connector.
With your multimeter in Volts DC mode probe the DK GRN/RD wire of the MAP sensor connector. The DK GRN/RED wire connects to the MAP sensor connector terminal labeled with the number 3 (in the photo above).
You'll need to use a tool like a wire piercing probe to access the signal inside the wire. To see what a wire piercing probe looks like, go here: Wire Piercing Probe.
Ground the black multimeter test lead directly on the battery negative terminal.
Turn the Key on but don't start the engine. At this point your multimeter should register about 3.8 to 4.0 Volts DC.
Now, pump the vacuum pump to apply vacuum to the MAP sensor. The voltage should drop down to 1.1 Volts.
Repeat this test step several times and each time, you should see the same values on your multimeter.
OK, let's take a look at what your vacuum pump test results mean:
CASE 1: Your multimeter registered the indicated voltages, on the DK GRN/RED wire, as you applied vacuum: This tells you that the manifold differential pressure sensor is OK (not defective).
Now, if your vehicle still has the MAP sensor code lighting up the check engine on your instrument cluster.. take a look at the section: MAP Code Won't Go Away for more info.
CASE 2: Your multimeter registered voltage, but it did not increase or decrease as you applied vacuum: This confirms that the manifold absolute pressure (MAP) sensor on your Mitsubishi is BAD. Replacing the MAP sensor will solve the MAP sensor trouble code lighting up the check engine light.
CASE 3: Your multimeter registered 0 Volts, on the DK GRN/RED wire, as you applied/released vacuum: This usually means that the MAP sensor is fried.
To be absolutely sure, we need to make sure that the MAP sensor is being fed both power and ground. If both are present, then we can conclude that the MAP sensor is BAD.
To test for power, go to TEST 2: Verifying The Manifold Absolute Pressure Sensor Is Getting Power.